As a result of complaints about noise from 2 large centrifugal fans on a factory roof and the involvement of the Environment Agency, the company spent £50k on traditional acoustic lagging that unfortunately had zero effect on the noise levels. This ineffective expenditure resulted in a prolonged wrangle with the authorities – who eventually suggested that they could get a 2nd opinion from us (based on our free analysis and diagnostic service).
They forwarded a video-clip and analysis of the sound-track proved that the problem was a pair of tones at the blade-pass frequencies of the 2 fans plus 1st harmonics that were interfering and “beating” with each other. We designed the solution in the form of aerodynamic Quiet Fan technology that provides retro-fit attenuation without using silencers. This eliminated the tones as a noise feature and the complaints ceased.
The whole process was completed within a few weeks at a tiny fraction of the cost of conventional alternatives. Moreover, only a single site visit was required – the rest of the work was carried out by email.
